Here's my setup:KA24DE-TGreddy TD06 / 20G turboRC 750ccZ32 MAFFMICEnthalpy ECUSAFCGreddy BOV Type S
I pull 350whp at the wheel with this beast, but I've always had compressor surge. My BOV doesn't release until I hit about 10psi. Anything below that is compressor surge. chew chew chew chewI use the Dec Air settings in the SAFC to prevent stalling. Even though I don't vent to air below 10psi, I can't turn off the dec air, or it will stall.
I decided to go recirc to rid myself of compressor surge and other things like richness during shifts, so I did tons of searching about it.I read that with the Greddy Type S, you need to remove the inner spring before using it as a recirc valve. I did that.Now I connected a hose to the outlet of the BOV and then back to my intake pipe in-between the turbo and the MAF.
Went for a ride...still had compressor surge.Next I tried to turn off the dec air settings...car stalls in between shifts.
Running out of time and frustrated, I removed the recirc tubing. I took it for a drive after turning the dec air settings back on.NO COMPRESSOR SURGE now, just psssshhhhh in between shifts when I get above 0psi.
I like the fact I have no compressor surge, but I can see how the psssssshhhhh can get annoying.Now for my questions/concerns.- Before I removed the inner spring, I had compressor surge meaning the BOV wasn't venting air to the outside. They why do I have to run the dec air settings in the SAFC to keep it from stalling?- When I recirc'd, why did I still have compressor surge and why did I still have to run dec air in the SAFC?
I want to go recirc and be able to turn the dec air settings off. The dec air setting is screwing with my idle for some reason.Oh yeah, I noticed something else. I have a wideband gauge and when the headlights or fan come on, I run rich for some reason. Anyone know why?
thanks in advance.
Really need some advice/help here - BOV, recirc, and SAFC
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Bronze MFP
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- Car: 1987 Nissan 300ZX w/digital dash radness
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your car is cursed, sell it!
I dunno man, normally people's setups run leaner when the headlights kick on. As for your BOV problem, who knows, maybe taking it apart unstuck something that was sticking previously. Most aftermarket BOVs will introduce low boost surge, in your case it took 10psi to even open the valve. After removing the spring, it eased the tension on the valve allowing it to open easier. downside is that it may leak under boost now.As for your SAFC, i'd say ditch that thing with a quickness and rom tune the stock ECU or go aftermarket
I dunno man, normally people's setups run leaner when the headlights kick on. As for your BOV problem, who knows, maybe taking it apart unstuck something that was sticking previously. Most aftermarket BOVs will introduce low boost surge, in your case it took 10psi to even open the valve. After removing the spring, it eased the tension on the valve allowing it to open easier. downside is that it may leak under boost now.As for your SAFC, i'd say ditch that thing with a quickness and rom tune the stock ECU or go aftermarket
Re: (Bronze MFP)
Thanks for the reply. I'm thinking about getting a larger alternator and doing a grounding kit to help solve the headlight and fan issue.
About the SAFC, yeah I hate using it, but my Enthalpy ECU is tuned for seal level and I'm at 7500 ft above it in Colorado. The car runs too lean up here so I need the SAFC to *** some fuel. I'm thinking about picking up a better FPR and just increasing the pressure to help push more fuel.This was suggested by Enthalpy. They are also giving me another tuned ROM to help with some idle and tip in issues I'm having with the 750cc injectors.
I figured, the looser spring tension in the BOV is what now makes it open easier. I boosted it to 15 psi last night with no leaks. I just don't know why I can't turn off the dec air settings on and SAFC when I run recirc. I'm going to try another recirc setup later next week and see what happens. Maybe I had the hoses all screwed up or something.
About the SAFC, yeah I hate using it, but my Enthalpy ECU is tuned for seal level and I'm at 7500 ft above it in Colorado. The car runs too lean up here so I need the SAFC to *** some fuel. I'm thinking about picking up a better FPR and just increasing the pressure to help push more fuel.This was suggested by Enthalpy. They are also giving me another tuned ROM to help with some idle and tip in issues I'm having with the 750cc injectors.
I figured, the looser spring tension in the BOV is what now makes it open easier. I boosted it to 15 psi last night with no leaks. I just don't know why I can't turn off the dec air settings on and SAFC when I run recirc. I'm going to try another recirc setup later next week and see what happens. Maybe I had the hoses all screwed up or something.
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Bronze MFP
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adrianfromthecastle
- Posts: 18849
- Joined: Wed Jun 29, 2005 5:36 am
- Car: 1992 Nissan 240sx
- Location: California
I'm taking it to a Nissan shop next week to get everything checked out. I should have done this the first week I got it, but was lazy and went to an generic performance shop. I paid $250 for a SAFC tune and that's all I got. I asked some questions about other things, but they didn't know too much.
This other shop specializes in 240SX's so I should be good to go. I'm going to get a leakdown and compression test, plus see if they can solve any other issues. They charge a flat labor rate for all the work they do. If any parts are needed, I pay extra.
The reason for going to a shop instead of pounding away at at home...I keep finding multiple little problems each day. Here's the current list:- oil has a slight hint of a gas smell- car blows white smoke on startup and when I get on it. not much smoke, but enough to see. It's not a headgasket, I've already checked the coolant.- car runs very rich on startup. Enthalpy says it's a tip in and idle issue with the 750cc injectors I'm running. They are sending me another ROM tune to fix the problem.- on startup, car blows out droplets of water coated in black soot. the black soot is probably from me running so rich all the time. water is condensation I'm assuming, but want to make sure- I want to go recirc and will let them figure it out. I tried and couldn't get it to work. I may try again, but I doubt it. Can't seem to figure out why I can't turn off the SAFC.
Thanks.
This other shop specializes in 240SX's so I should be good to go. I'm going to get a leakdown and compression test, plus see if they can solve any other issues. They charge a flat labor rate for all the work they do. If any parts are needed, I pay extra.
The reason for going to a shop instead of pounding away at at home...I keep finding multiple little problems each day. Here's the current list:- oil has a slight hint of a gas smell- car blows white smoke on startup and when I get on it. not much smoke, but enough to see. It's not a headgasket, I've already checked the coolant.- car runs very rich on startup. Enthalpy says it's a tip in and idle issue with the 750cc injectors I'm running. They are sending me another ROM tune to fix the problem.- on startup, car blows out droplets of water coated in black soot. the black soot is probably from me running so rich all the time. water is condensation I'm assuming, but want to make sure- I want to go recirc and will let them figure it out. I tried and couldn't get it to work. I may try again, but I doubt it. Can't seem to figure out why I can't turn off the SAFC.
Thanks.
Re: (saejin)
Is the BOV adjusted properly. In my experience you only should ahve 1/4" above the nut showing.
The gas smell in oil is somewhat/kinda normal. It's a turbo car remember. As long as it isn't to thinned out or gasy you're ok. A slight smell isn't hurting anythign.
The white smoke (which is probably black) is also normal. Again, turbo cars will burn some fuel when you accelerate, and leave some smoke. If your headgasket was blown, you would notice coolant loss, and anyone behind you would be getting some coolant film spray on their car when you boost.
FWIW: Glad you at least called Enthalpy and discussed the issue. Way to many people just start changing stuff without asking. Props for that!
PS: Ditch that AFC asap.
The gas smell in oil is somewhat/kinda normal. It's a turbo car remember. As long as it isn't to thinned out or gasy you're ok. A slight smell isn't hurting anythign.
The white smoke (which is probably black) is also normal. Again, turbo cars will burn some fuel when you accelerate, and leave some smoke. If your headgasket was blown, you would notice coolant loss, and anyone behind you would be getting some coolant film spray on their car when you boost.
FWIW: Glad you at least called Enthalpy and discussed the issue. Way to many people just start changing stuff without asking. Props for that!
PS: Ditch that AFC asap.
Re: (codyace)
Update:
Redid the recirc again and it still didn't work. I think the problem lies with my inlet pipe on my intake that I plumbing the BOV back into. I did removed an inner spring on the BOV, so I know it opens very easily.It worked at idle and when I reved it to 2500rpm, I had no problems. When I went past 2500rpm, the car stalled and died one the way back down. I assume this is becasue more air is coming out of the BOV and the inlet can't keep up.I'm going to weld a larger inlet, like 1inch or 1 1/2 inches. It's currently only a 1/2 large.
Well, I went back to the open BOV, but changed it up a bit. Since it was leaking with just one spring, I put the other one back in. Now with both springs, it won't open until 10psi which causes massive compressor surge. So, the BOV has two nipples on it. The upper is for vacuum/boost and the lower is for boost only. I nver had the lower hooked up before, but decided to give it a try.I found a boost only source and hooked it up. Went for a drive and now the BOV opens no problems and I don't have anymore surge. It acts like a push/pull BOV now.
Enthalpy has been great. Scott has a new person working with him that's taking care of all the administrative emails and such...leaving Scott to work on tuning. This has worked out great becasue all my questions have been answered in great detail. They are working on a retune for me and I've been giving them some feedback on my current tune. Enthalpy is great and I'd recommend them to anyone.
Redid the recirc again and it still didn't work. I think the problem lies with my inlet pipe on my intake that I plumbing the BOV back into. I did removed an inner spring on the BOV, so I know it opens very easily.It worked at idle and when I reved it to 2500rpm, I had no problems. When I went past 2500rpm, the car stalled and died one the way back down. I assume this is becasue more air is coming out of the BOV and the inlet can't keep up.I'm going to weld a larger inlet, like 1inch or 1 1/2 inches. It's currently only a 1/2 large.
Well, I went back to the open BOV, but changed it up a bit. Since it was leaking with just one spring, I put the other one back in. Now with both springs, it won't open until 10psi which causes massive compressor surge. So, the BOV has two nipples on it. The upper is for vacuum/boost and the lower is for boost only. I nver had the lower hooked up before, but decided to give it a try.I found a boost only source and hooked it up. Went for a drive and now the BOV opens no problems and I don't have anymore surge. It acts like a push/pull BOV now.
Enthalpy has been great. Scott has a new person working with him that's taking care of all the administrative emails and such...leaving Scott to work on tuning. This has worked out great becasue all my questions have been answered in great detail. They are working on a retune for me and I've been giving them some feedback on my current tune. Enthalpy is great and I'd recommend them to anyone.